I have to say, for me it is a purchase decision killer.
Put two knives in front of me, and make them identical except the steel, and I am going to choose the better steel.
I won't knowingly purchase one in 420HC.
440C ? Sure, I'd love to try out some with known, quality heat treat. I have an old custom that is, likely, but have never used or sharpened it, because it is irreplaceable to me. I like S&M's ATS34 fine. D2? Excellent. 154CM or CPM 154 I am very satisfied with.
I realize that 1095 is not high end steel, but it has its own endearing qualities that keep me coming back. Most of my traditional are this steel from GEC.
I even like Opinel's carbon steel. Softer than GEC's 1095 by a bit in my experience, but still easy to sharpen very sharp, and easy to maintain. But again the price is nearly free!
That said, I am testing out some Buck knives which I am sure are 420HC. I think in the Buck price range, and with the consistent Heat treat they have the reputation for, it will probably serve me just as well as 1095.
I have an AG Russell large sod buster in stainless, but I honestly don't know how it compares to 420HC. I am satisfied with it so far, but again, it is in a different price category.
I find my self pleased with the edge I can get on Opinel's INOX steel, as well as its edge holding. Again, it's in a completely different price class, though.
I guess I am kind of a steel snob. Kind of, just a little bit.